1. Technical Field
The present disclosure relates to a data relay apparatus that receives a request for content data, transfers such a request to a server apparatus, and transfers content data sent from the server apparatus in response to such a request in information centric networking (ICN). The disclosure also relates to such a server apparatus, a data relay method, and a data sending method.
2. Description of the Related Art
Lately, a technology referred to as ICN for obtaining content data by specifying, not a location at which the content data is disposed, but a name of the content data itself has been proposed. A typical example of ICN is content centric networking (CCN) disclosed in the following literature: U.S. Patent No. 2012/0317616; Van Jacobson, Diana K. Smetters, James D. Thornton, Michael F. Plassi, Nicholas H. Briggs, and Rebecca L. Braynard. Networking Named Content. ACM CoNEXT, 2009; Giovanna Carofiglio, Massimo Gallo, and Luca Muscariello. Icp: Design and evaluation of an interest control protocol for content-centric networking. INFOCOM NOMEN Workshop, 2012; Giovanna Carofiglio, Massimo Gallo, Luca Muscariello, and Michele Papalini. Multipath congestion control in content-centric networks. INFOCOM NOMEN Workshop, 2013; Stefano Salsano, Andrea Detti, Matteo Cancellier, Matteo Pomposini, and Nicola Blefari-Melazzi. Transport-layer issues in information centric networks. ACM SIGCOMM ICN Workshop, 2012; and Somaya Arianfar, Pekka Nikander, Lars Eggert, Jorg Ott, and Walter Wong. Contug: A receiver-driven transport protocol for content centric networks. IEEE ICNP, 2010.
In this technology (ICN), in order to obtain content data, a user terminal apparatus sends a request packet that specifies, not a location at which the content data is disposed, but a name of the content data itself, to a network. Then, upon receiving the request packet, a content providing apparatus (server apparatus) sends a data packet of the content data corresponding to the name of the content data.
A relay node that relays data serves to forward a request packet to a content providing apparatus and to forward a data packet to a user terminal apparatus in accordance with a routing table. The relay node also serves to concentrate the traffic by using a pending interest table (PIT) and a content store (CS). In CCN, by utilizing these mechanisms, when multiple users attempt to obtain the same piece of content, data is distributed by making the best use of a cache in a network.